Because the quality of this drink depends on the quality of the fruit, buy a ripe, deep colored watermelon in season. You are after a consistency not much thicker than lemonade so adjust the water accordingly.

This will keep a couple of days in the refrigerator and will be safe to drink for longer than that, but the texture changes and the taste fades so it's best when used the same day. For a party, it's lovely to make another batch using a yellow watermelon or a cantaloupe, and a pale green one with honeydew melon.

• 4 to 6 cups watermelon, peeled, chopped into chunks and seeds removed (or use a seedless melon, or blend with the seeds and let the debris settle to the bottom of the blender before pouring into the pitcher)
• 1/2 cup sugar (optional)
• Few drops lemon or lime juice (optional)
• Water

1. Place the watermelon in a blender with 3 cups water and blend until smooth. Pour into a gallon pitcher and add more water to make a gallon of beverage.

2. Taste and add sugar if necessary, stirring until dissolved. If the watermelon is not quite at its peak and the flavor needs brightening, add lemon or lime juice to taste. Chill. Stir before serving.